Domestic heating process and apparatus therefor



Dec. 24, 1935. R. M. STEWART DOMESTIC HEATING PROCESS AND APPARATUSTHEREFOR Filed June 15. 1934 5 Sheets-Sheet 1 Dec. 24-, 1935. R. M.STEWART DUMESTIC HEATING PROCESS AND APPARATUS THEREFOR Filed June 15,1934 3 Sheets-Sheet Dec. 24, 1935. R. M. STEWART DOMESTIC HEATINGPROCESS AND-APPARATUS THEREFOR -Filed June 15, 1934 5 Sheets-Sheet 5 a Wa A? w 553 m? Patented Dec. 24, 1935 PATENT OFFICE R DOMESTIC HEATINGPROCESS AND APPARATUS THEREFOR Richard M. Stewart, Montclair, N. J.,assignor to Ellis-Foster Company, a corporation of Ne Jersey ApplicationJune 15, 1934, Serial No. 730,711

4 Claims.

This invention relates to a method of generating and dispersing heatthroughout the interior 5 of heat transference, such as radiators,together with the apparatus for that purpose.

This process may be applied to heating by any of the usual means such assteam, hot water, either with open or closed expansion tank, warm air,or by heating employing a pressure lower than atmospheric. The inventionmay also be used to furnish hot water for any purpose such as the supplyof buildings.

The application of this method will be illustrated by a domestic heatingplant of small proportions, but the invention is not limited to such useand may be applied to large installations or industrial heating of anynature where the usual means of heat transference may be employed. Thefuel used in this example is illuminating gas, that is city or town gas,either natural and/or artificial, but this does not preclude the use offuel oil, coal tar,'powdered coal, still residues, or other morevaluable fuels or any combination of these.

As the supporter of combustion I may use ordinary air, or air which hasbeen dried or humidified or air enriched by'the addition of oxygen,although satisfactory operation may be obtained except under severeservice conditions without such means. Preheating may be employedeitherfor the fuel or supporter of combustion but its use is not essential tothe process unless a low grade of fuel is employed and this is notillustrated 'in the method shown here. p

The pressure required for the operation of the process may. be greaterthan atmospheric as in the case of steam or hot water, atmospheric asshown in the example here, or less than atmospheric as in the case ofvapor systems.

The medium of transfer used in this example is water, but this does notpreclude the use of other heat-stable liquids which may be suitable forthe purpose.

When applied to heating as described herein, submerged combustion hasmany advantages, tending to simplify the equipment necessary for thegeneration-of heat, increase the efficiency of the process, and decreasethe cost of the equipment required.

Since the exhaust-gases from the burner pass directly through the mediumof heat transfer, they are removed at the temperature of the liquidthrough which they pass. The gain in efiiciency resultant from thismethod is, of course, large, 5 the thermal eificiency shown by thismethod is well above per cent. Furthermore,- since these exhaust gasesare forced from the system by the differential air density between thegases andthe medium of transfer, a. draft is'not required 10 and thenecessity for a flue is dispensed with.

In this process an ordinary malleable iron pipe of, say, an inchdiameter, is all that is required to replace the .usual expensivechimney. When the pipe is used as a heat exchanger for the preheating ofthe fuel supply, even the small heat waste, represented by the extremelysmall difference between the temperature of the medium of transfer andthe temperature of the air used to support combustion, may be reduced toa negli-.

. gible amount. I prefer, however, to' omit such additional apparatus indomestic heating systems as described herein.

Inasmuch as I may put the heating unit at the top of the system, as inFig. 1, instead of at the 25 bottom, as is the usual case, thecellar isleft entirely free of all heating equipment, and it is not necessary toheat that portion of the building unless it is desired to do so.- Theheating plant may then be placed in space which is usually 30 wasted andis of such compact design that it occupies far less room than theconventional type of unit with the same equivalent radiation. There may,however, be cases where it would be preferable to place the heating uniton the same horizontal plane level as the radiators or other means ofheat dispersion. Such a system is illustrated in Fig. 3, where theheating unit is placed in a small enclosure outside the main dwelling.If desired, the heating unit may be placed within the building in, say,a closet and operation will be equally satisfactory.

' Under certain conditions it may be desired to place the heating unitbelow the radiating 5 elements of the system. I prefer not'to do thisbecause of the more elaborate compressors required to force the fuelinto the burner against this larger water pressure, but if so desiredthe unit may be utilized in this manner. When the 50- heating unit isplaced at the bottom of the circuit, circulation is of course extremelyrapid, since it is impelled by the combined forces of convection andpressure at the mouth of the burner. Circulation in this system is dueto the pressure of the burner g'ases impinging on the liquid at themouth of the burner and not to the lifting effect of the entrapped gasparticles over a large vertical distance. Because of this it is notessential that the burner be placed under considerable water pressurewith the disadvantages of injection mentioned above.

Since the heating system as shown here is entirely sealed with theexception of the air intake and exhaust, which are outside the building,there is no possibility of leakage of noxious fumes or gases insidethestructure. Inasmuch as the heating unit itself requires no floorspace, it may be hung from the wall or placed in accessible dead airspaces. 0

Whengas is used as a fuel, there is no need of bins or storage tanks andthe supply of fuel is entirely automatic. When the system as describedhere is combined with a thermostat placed within the structure ormaterial to be heated, the control of heat becomes self-regulating.

Since the elements of the heating unit are'principally of tubular shapeand of relatively small dimensions, the apparatus may be made entirelyof malleable iron or corrosion resisting material without making thecost of the system prohibitive.

Due to the fact that the circulation of the medium of transfer is causedby the pressure of the exhaust gases at the mouth of the burner, therebyproducing a considerable pressure head, the circulation is not dependenton a large difference in elevation of the heater and radiating units as.40 is the case when circulation is due" to convection currents. 0n theother hand, the head produced by this method is suflicient to supportcirculation over any height feasible with the usual systems.

This is of particular value in one-story cone struction, since it is notnecessary to place the heating unit lower than the balance of thestructure.

Aside from the heating unit as described herein, the piping and unitsfor radiation are of the.

conventional type and do not necessitate any special equipment, orparticular methods of piping, so that this heating unit may readily beadapted to systems which have formerly utilized some other type ofheating unit. Because of the extremely'small amount of water which isrequired in the heating unit, practically the entire amount of water isin the radiators and piping circuit, thus lessening the amount of waterwhich must be heated and so greatly reducing the time which is requiredto bring the system to full heat.

'Due to the fact that the movement of the medium of heat transference isnot due to convec- ,tion but to a pressure head circulation startsimmediately when the burner is lighted, thus making this a most flexiblesource of heat.

The entire unit is free from small orifices, com- 'plex mechanicaldevices, and other trouble-making features. r The cost of this systemboth fromthe standpoint of installation and equipment should be far lessthan that of any other comparable apparatus of equal heating effect andthe operating cost will also-be-less than that of other systems using 7the same The invention is illustrated by the appended drawings, in whichsimilar reference numbers de- .note similar parts.

The general elevation, Figure 1, represents an installation using hotwater as the medium of heat 5 transference together with the usualradiators employed in such as'ystem;

It will be seen that the usual methodof double piping from headers'isemployed, the only variation from the conventional system being that the10 heating unit is placed in waste space at the top of the structureinstead of in the cellar. The direction of circulation through thesystem is indicated by arrows, but it is of course possible to oper ateany one or any combination of radiators if so 15 desired. The method ofleading the exhaust gases to the roof vent, consisting merely of alength of piping, is also shown.

Figure 2 illustrates the heating unit in detail. Illuminating gas andair, the components of the 20 combustible mixture chosen for thisexample, are drawn into the apparatus through the needlevalves at I and2 respectively. These valves are adjusted to give the proper mixturewhen the apparatus is first installed and it is not necessary-to 25 setthem thereafter. In the mixing chamber, 3, the gas and air arethoroughly intermingled to give an intimate mixture and they then passthrough the supply line, 4, to the compressor, 5,

where they are raised to a pressure slightly above 30 atmospheric. Inthis example a rotary compressor of the gas booster type maybe used buta compressor capable of giving greater pressures may be used ifrequired.

The .pipe, 6, leads the compressed mixtureto 35 the nozzle, 1, where itis discharged into the burner at a velocity greater than the rate ofbackfire. The burner casing is lined with some heat-resistant substance,either of refractory or metallic through the burner mouth, 8. Thisopening may 45,

be covered by a small perforated plate designed to break up the gasesinto a large number of minute bubbles which give up their heat to thewater in the region of heat transfer, 9, between the burner mouth, 8,and the exhaust pipe, II. or other circulating medium, is forced throughthe burner casing in the direction indicated by the arrows under theimpetus of the pressure of the gases leaving the burner mouth. Thegeneral water level is shown in Figure 2, but this is of 5 course onlyapproximate since the level will be 'higher at ll than at l5 by theamount representing the head tendency to circulate the water. I

At the water level the gases separate from the liquid, while the waterpasses down the header, 60

l0, and so to the heating system. Liquid returns from the radiators bythe header, l2, and so passes through the heater again, flowing in theannular space between the burner and the casing 65 o the heating unit.Since it is'possible that from timeto time a small amount of gas shouldpass up the annular space, an air trap might form at the junction, [5,if it were not for the. bypass, l6, which removes any such gas whichmight 0011866. This is only an incidental feature, however, and notessential to the operation of the burner, Under certain conditions itmay be desirable to preclude the'possibility of noise traveling tothe-radiating elements from the heating unit. This may 76 Thewater, 50 jbe done by the use of rubber fianges, 48, as shown.

Although I may operate the heating unit under a considerable head ofwater, I prefer to so place the burner so its highest point is just atthe water level, thus completely surrounding the burner with liquid andstill keeping the pressure within the burner at a minimum. The level ofliquid within the burner is kept at the correct point by the use of atank, I 3, equipped with a float valve and supplied from the water'mainsby the feed pipe, M. This tank serves both to compensate for theexpansion of the liquid upon heating and also to supply the system withwater as needed.

This arrangement of the supply and expansion tank is not essential for,as in Figure 4, Imay greatly enlarge the heating unit at the point I8,

where the gases escape from the liquid, and use this for the purposes ofsupply and expansion.

As shown in Figure 2, I may light the burner by passing a spark from thecontact, II, to some point within the burner, such as the orifice I, but

under some conditions it might be preferable to ignite the mixture bymeans of a glow bar or by a pilot light.

Figure 3 illustrates another method'of placing the heatingsystem. Inthis case the level of the water in the burner may be placed as low asthe tops of the radiators in the circuit. The details of the heatingunit used here are identical with those illustrated in Figure 2. Again Iprefer to operate the burner with the minimum head, as explained above.

Figure 4 illustrates an adaptation of this burner to the method of warmair heating. The heating unit again is similar to that shown inFigure 2,except as to the arrangement of the supply-expansion tank, as explainedabove. In this case, however, the radiator, I9, is placed within a ductwhich is supplied with air entering at 23. Circulation of the air issecured by convection'but a fan, 2|, may be used to increase'thevelocity of flow, if desired. A screen, 22, may be used to clean the airof dust particles and a spray, 20. falling into the catch basin, 25,represents a possible means of humidifying the air. After passing overthe heating element, l9,'the air is then led through the duct, 24, tothe points to be heated, where it is discharged through registers orgrilles. Figure 5, illustrates a means by which submerged combustion maybe adapted to the heating of water or other liquid for useother thanheating purposes. The tank, 29, may be the sole method of storage or theliquid may pass through the outlet, 28, to another tank used for storagepurposes. Heating is accomplished by surrounding the heating unit withfins, 26, to create a large heating area and submerging the unit in theliquid to be warmed. Cold water from the supply I line is supplied at21. The supply-expansion tank as well as the apparatus .for the supplyof fuel is omitted in this figure for the sake of clarity. Numbers 6,l6, and II have the same significance as in Figure 2.

Figure 6 shows an adaptation of submerged combustion to vapor heating.Operation here is identical with that of Figure 2, except that there isno circulation of water. .The water level shown is maintained by thestorage tank, 30, and the burner raises the temperature of the liquidcontained in the heating unit to a point such that the liquid vaporizesand is carried up with the exit gases from the burner to the radiators,4 I, through the header, 41. The radiators are equipped with valves, 44,to permit shutting off unnecessary units. If desired valves, 43, may beplaced on each radiator either to maintain a certain pressure within thesystem or else to maintain the heat within the radiators at the bestpoint. The condensed vapor runs back through the piping to the chamber,40, containing a deflector not shown, 5 so that this liquid is bypassedinto the annular space between the burner casing and the walls of theheating unit. The exit gases which contain no excess vapor are thenallowed to escape through the header, 46, to the roof vent, 42.

In both this figure and in the following figure,

"7, the fuel supply apparatus has been omitted.

Figure-"l illustrates a method of using other submerged combustionheating units for both space heating or water supply heating.

-With valves 33 and 35 closed and valves 34 and 36 open, operation isthe same as in Figure 2. When valves 33, 34, and 36 are closed and valve35 open, the unit may be used to heat the water in tank 29 by means ofthe radiator 32. Cold water 20 enters the tank at 21 and the warm watermay be drawn off at 26. When valves 34, .35, and 36 are open, and 31 isclosed, the unit may be used simultaneously both for space heating andfor the heating of water. supply. Circulation of the 25 medium of heattransfer to radiators is through the supply header, Ill, and the returnheader, l2, as in Figure 2.

For certain purposeswhere hot water is required, this may be drawndirectly from the sys- 30 tem through valve 33. Fuel supply is identicalwith that shown in Figure 2. y

In some cases it may be found desirable to use a. pump to aid thecirculation of the liquid through the system. Such a device is not shown35 in the drawings, since in general its use is not necessary. oradvantageous, but such use is not precluded.

What I claim is:

1. The process of heating and circulating a 40 liquid medium of heattransfer within a heating systemwhich comprises the ejection of theproducts of combustion from a burner submerged in the liquid into theliquid in the direction of cir-- culation' of the liquid, said burnerbeing so ar-'- 4 ranged that the hydrostatic head is greater at thepoint of entry of the exhaust gases into the liquid medium of heattransfer than at the point of introduction of the combustible mixtureinto the combustion chamber. 2

2. The process of heating, and circulating a liquid medium of heattransfer within a heating system which comprises the ejection of theprodnets of combustion from a burner submerged in the liquid into theliquid in the direction of citculation of the liquid, said burner beingso arranged that the point of entry of the combustible gases into theburner chamber is not under pressure due to hydrostatic head of theliquid medium of heat transfer. 0

3. The process of heating and circulating water within a heating systemwhich comprises the ejection of the products of combustion from a burnersubmerged in the water into the water in the direction of circulation ofthe water, said burner being so arranged that the hydrostatic head isgreater at the point of entry of the exhaust, gases into the water thanat the point of introduction of the combustible mixture into thecombustion chamber. I

4. In a heating system a portion of thei'watercontaining circuitcomprising two tubular units joined at an'angle of less than 180to forman erect V-shaped structure and containing within one ofthe membersadownwardly directed bum- 4 2,025,090 er submerged within the liquidmedium of transthe hit due to gas entrapped in the medium of fer in sucha manner that the liquid withinthis transfer and then, after the removalof exhaust portion is impelled, directly following the appligases fromthe liquid, flows downward to supply cation of heat, in an upwarddirection in the heat to the balance of the circuit. opposite arm due tothe combined impetus ol the 5 pressure of the exit gases from the burnerand RICHARD M. STEWART.

